In order to save energy at a building, such as a house, a factory, an office building, a commercial building, a hotel, a hospital, etc., at operation time, it is necessary to manage operation states of various facilities of the building in some way, such as opening or closing states of windows and doors of a target building, use states of rooms, number of persons in a room, working states of an air conditioning system, air conditioners, ventilators, boilers, etc.
In order to provide such a system, etc., for example, Patent Literature 1 has disclosed a system in which energy consumption of a facility machine that is artificially operated is measured, and if a discrepancy between the energy consumption and a target value artificially determined in advance becomes large, a warning, etc., is output. Also, Patent Literature 2 has disclosed a method of directly controlling facilities on the basis of measured energy consumption values of facilities and management target values determined by a system. And at that time, the method uses, for example, a comfort index (Predicted Mean Vote (PMV)), etc., on air conditioning as management target values. Also, Patent Literature 3 has disclosed a building-operation optimization support system. In the building operation optimization support system, simulation is used for optimization of operation conditions, and operation data in the case of actually operating a building on a first operation condition is multiplied by a ratio of a simulation result based on the first operation condition to a simulation result based on a second operation condition so that operation data is calculated on the assumption that the building is operated on the second operation condition in order to improve precision of the simulation. Thereby, necessity of operation, management or adjustment by a skilled person has been drastically reduced.
However, in all these systems, an individual target building is only operated independently, and there has been a problem in that degree of energy saving depends on knowledge and skill of an individual person who is in charge of operation management of the building. Also, since there is no building having the same environmental condition and building structure, it is not possible to objectively grasp to what extent energy saving is possible for a building ideally while energy saving is carried out for the building individually. Further, it is possible that there is a building in which smarter operation is performed among many buildings and facilities than the target building. However, it is not possible to find such facilities and buildings in consideration of a difference in environmental condition, and also not possible to make reference in order to save energy for the target building. Accordingly, there has been a problem with that degree of energy saving of each building is substantially divided and insufficient.